Spark-plug.



AMOS N. HOAGLAND, OF OXFORD, NEW JERSEY.

SPARK-rites.

Specification of Letters Patent.

Patented Sept. 21, 1915.

Application filed August 2, 1911. Serial No. 641,905.

To all whom it may concern Be it known that I, AMos N. HOAGLAND, a

- citizen of the United States, and a resident ments and combinationshereinafter of Oxford, county of Warren, and State of New J ersey, haveinvented a certain new and useful Improvement in Spark-Plugs, of whichthe following is a specification. I

My invention relates to spark plugs wh ch are adapted for the ignitionof explosive charges in hydro-carbon engines.

Among the objects of my invention are the provision of a spark plug withmultiple sparking points; the provision of a spark plug in which thepoint or points are readily movable and removable and replaceable, theprovision of a spark plug which is not readily fouled and in which theinsulation and inner conductor is protected from fouling by the meanscarrying the sparking points, and the provision of a spark plug in whichthe distance between the points is adjustable to control the length ofthe spark gap by positive adjusting means without the necessity ofresort-ing to bending of parts or deformation of any character.

Other objects of my invention will ap pear in the course of thefollowing specification and claims.

WVith these and related objects in view, my invention consists in theparts, improveset forth and claimed. 1

\Vhile I have illustrated and shall describ the preferred embodiment ofmy invention, it will, of course, be understood that my invention is notlimited to the specific form illustrated and described, but is as broadas my claim.

In the accompanying drawings in which the same numerals of reference areuniformly used to designate the same parts throughout, Figure 1 isavertical, central, cross-sectional View of a spark plug embodying thepreferred form of my invention, and Fig. 2 is a similar fragmentary Viewof a modification.

Reference numeral 1 designates .the outer shell of the spark plug. Thisshell may be of any known form. In the illustration I have shown it ashaving a threaded portion 2 adapted to be screwed into a threadedopening in the engine cylinder, and a squared or hexagonal portion 3 towhich a wrench or other tool can be applied. In the form shown ashoulder 4 is formed between the screw-threaded and the squared orhexagonal portion, but as already stated, this shell may be of anypreferred and usual form,- according to the form and construction of thecylinder in which it is to be used.

Reference numeral 5 designates the insulating means which is preferablyof orcelain, but, of course, any equivalent insulator may be substitutedfor the porcelain. The insulator 5 is provided with an enlarged portion6 between its ends, which is received fairly snugly within the opening 7in the shell 1, and rests on the shoulder 8 in said shell. The insulatoris held in place in the shell by means of the retaining nut 9 which, isapertured at 10 to permit the passage of the insulator, and is providedwith an exterior screw thread by means of which it is screwed within theinteriorly threaded opening 7 of the shell 1. Suitable packing 11 issupplied at each end of the enlargement 6 of the insulator 5 in order tomake the spark plug gas tight. The insulator 5 is provided with an axialperforation 12, which perforation is enlarged at its lower end to formthe recess 13. Through this longitudinal perforation in the insulator ispassed the stem 14: of conducting material. Near its lower end, thisstem, which is preferably threaded substantially throughout its length,is enlarged at 15 to an extent nearly but not quite suilioient to closethe end of the recess 13, thus making a substantially dead air spacewithin the interior of the recess 13, retarding and preventing depositof carbon therein, and greatly lessening the liability of the plug tobecome fouled and short circuited. The removable point carrying member17 may be secured against the shoulder 16 pro vided at the lower end ofenlargement;l5. This point-carrying member 17 is preferably providedwith a central screw-threaded opening so that it may be screwed on thestem lit to abut against the shoulder 16, and may be firmly secured in.place by means of the lock nut 18. It is not essential, of course, thatthe point-carrying member 17 be threaded and screwed on the stem 14, itbea deflection of the with it. 1

Nut '20 is screw-threaded on the stem 1t above the shoulder 15, and isreceived within the recess 13 in the insulator 5, and abuts against theinner extremity thereof, thus providing means of adjustment of thestem.14: and the spark point-bearing member 17 "which is attached theretowith reference to the' shell 1 of the plug.

I A nut 21 is pro- 'vided for securing the outer end of the stem 14 tothe insulator 5, and an additional nut 22 is' 'provided for the purposeof making the requisite electrical connection. 1 If it is desired toadjust the plug so as to increase or decrease the length of the sparkgap, this result may be secured by loosening nuts 22 and 21 and rotatingthe threaded stem 14 with respect to the nut 20 in which manner thepoints 19 may be made tov approach or recede from the end of theshell 1. W hen it is desired to replace the spark-points the nut 18 andspark point carrying member 17 (if the latter is screwthreaded on thestem) are unscrewed from the stem 14: and the point-bearing memberducting material, and having a central 1011-.

gitudinal aperture, an insulatorwithin the aperture in the saidshell,said insulator being provided with a longitudinal aperture enlarged atits inner end, a stem passing through the aperture in said insulator,and a nut on the said stem fitting Within the enlargement or saidaperture, said stem being enlarged beyond the said nut to substantiallyclose the aperture in the insulater, a shoulder on said stem, and apoint bearing member carrying a plurality of spark points removablysecured to said stem and. abutting against said shoulder, substantiallyasset forth.

This specification signed and witnessed this 31st day of July, 1911.

AMOS N. HOAGLAND. i/Vitnesses ROBERT S. ALLEN, Enw. J. GEORGE.

